asp.net - Disable ASP.NET_sessionId

In one of the applications I developed we did not want to store any cookies for legal issues.Hence we had to disable all the cookies.While testing the application on the test servers I noticed the following Asp.Net_sessionId cookie being set.

More about it here on msdn (http://msdn.microsoft.com/en-us/library/ms178194.ASPX)

We still didn't want to use it even though it was non persistent since we were not allowed to create any cookies.One workaround is to disable the session state on IIS for the site.

Note:You will not be able to use Session if you do this.

 

SqlDependency must be called for each server that is being executed

Recently we rewrote our web applications in VS 2012 and .Net 4.0 and hosted it on IIS 7.For caching content I used the Sql Dependency and SQL service Service Broker.On test environment with load balancing we had two servers configured and everything was working as expected.

However when I moved the applications to production I started getting this error.

The only difference was the connectionstring which specified a failover server.

<add name="CONTENTDSN" connectionString="Data Source=Server1;Failover Partner=Server2;Initial Catalog=Database_Name;uid=UserId;pwd=password;"/>

The error was due to the failover server not having the database objects.Now when you use SQL dependency make sure that the failover server i.e Server2, has all the necessary database objects as the main server i.e. Server1.

asp.net - Could not load type

Today while I was converting a Web Application to a WebSite in Visual Studio 2012 I came across this error.I created a new website and starting adding the pages from the web application.Once I was done adding the pages, I did a build on the website and I encountered the "Could not load type ' '" error in my website.

After searching for an answer I found this error can occur for various reasons, in my case though it was because of the CodeBehind attribute of the aspx pages.When you add a aspx page to a web application the CodeBehind attribute is set.

<%@ Page Title="About Page" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="About.aspx.cs" Inherits="About" %>

If you import this page into a website you will come across Could not load type About error.The fix was to change the attribute to CodeFile in the website aspx page

<%@ Page Title="About Page" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeFile="About.aspx.cs" Inherits="About" %>

See here for CodeFile vs CodeBehind
http://stackoverflow.com/questions/73022/codefile-vs-codebehind

c# - List strings in order of occurrence in a given string

In the project that I am working on right now I had to figure out a way to list a given set of strings in another string based on the order in which the list of strings would occur.

For example: I have a few raw html page content extracted from the web and I have a list of words.The task is to build a grid display that would list those words in order of occurrence in the content of a page. 

Below is the sample code using a console to achieve it.If there is a better way to do this, I am interested to know.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace StringOrder
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                //Set of random words to search for in Content
                string[] saArrayofStrings = { "abc", "def", "mno", "xyz", "jkl" };
                //Content
                string sString = "xyz The history of the United States as covered in American schools and universities typically begins with either Christopher Columbus's 1492 voyage to the Americas or with the prehistory of the Native peoples, with the latter approach having become increasingly common in recent decades.[1]jkl Indigenous peoples lived in what is now the United States for thousands of years and developed complex cultures before European colonists began to arrive, mostly from England, after 1600. The Spanish had early settlements in Florida and the Southwest, and the French along the Mississippi River and Gulf Coast.abc By the 1770s, thirteen British colonies contained two and a half million people along the Atlantic coast, east of the Appalachian Mountains.mno The colonies were prosperous and growing rapidly, and had developed their own autonomous political and legal systems. However, with the end of the French and Indian War in 1763, Great Britain altered its relationships with the colonies by imposing tighter administrative controls and greater financial obligations on the colonists [2]. Tensions grew, eventually leading to armed conflict beginning in April 1775. def On July 4, 1776, the colonies declared independence from the Kingdom of Great Britain.";
                SortedList<int, string> OrderList = new SortedList<int, string>();
                foreach (String s in saArrayofStrings)
                {
                    if (sString.Contains(s))
                        OrderList.Add(sString.IndexOf(s), s);
                }
                Console.WriteLine("The order of occurrence of the given list of words in the content is below");
                foreach (KeyValuePair<int, string> pair in OrderList)
                    Console.WriteLine(pair.Value + " occurs at the following position:" + pair.Key.ToString());
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            Console.Read();
        }
    }
}

Output:

Visual Studio 2012 - The type or namespace name '' could not be found (are you missing a using directive or an assembly reference?)

In Visual Studio 2012 if you encounter this error when you add a new class to the solution,check to see the build action of the class in the properties of the class.
By default the build action is set to 'content'.Change it to 'compile'.See below

vs 2012 - The primary reference could not be resolved because it has an indirect dependency on the framework assembly

I started getting this error after changing the target framework in build configuration for my web application in Visual Studio 2012.

To resolve this I had to unload the project and reload it into the solution.Right Click on the application in VS 2012 solution and select Unload Project in the context menu.

Reload the project by right clicking on the project that is not available

asp.net - Method not found: 'Void System.Web.UI.ScriptResourceDefinition.set_LoadSuccessExpression(System.String)'.

You will get this error if you try to host your application on IIS Application pool running on .Net. 4.0 and your web application is built in .Net 4.5.By default the selected target framework for Visual Studio 2012 is .Net 4.5.

Right Click on your application in Visual Studio 2012, select the build configuration and choose .Net 4.0 framework.

asp.net - System.BadImageFormatException: Could not load file or assembly '' or one of its dependencies. An attempt was made to load a program with an incorrect format

You will get this error if you try to host a 32 bit web application on IIS7.To fix this error set "Enable 32 bit applications" flag to true in AppPool Advance Settings.

vs 2012 - The following module was built either with optimizations enabled or without debug information

I started getting this warning window while debugging one of my projects and to workaround it I had to change my debugger settings.

asp.net - Access Master Page Label from Content Page

The below screenshots show how one can have a label on master page for displaying messages to the user using the application.

Site.Master 

Site.Master.cs 

Default.aspx 

Default.aspx.cs

Saving changes not permitted

If you try to use the SQL Server designer for making changes to the table you just created, then you will get a dialog box that tells you that you cannot save the changes.One work around this issue is to disable the option "Prevent saving changes that require the table to be re-created".

To disable this option see the screenshots below.

HTH

asp.net - OutputCache, page level caching dynamically

I wanted to setup page level caching for one of the web application I was building since the content of the site came from a database and the content was not updated frequently.
Instead of using the declarative syntax
<%@ OutputCache Duration="20" VaryByParam="param1;param2"%> 
I use the following CachePage() method that enables caching based on configuration entries.

More on various caching techniques here (http://msdn.microsoft.com/en-us/library/y18he7cw(v=vs.100).aspx)

The following configuration entries help control how often the pages are to be cached and the query string parameter values that would invalidate the cache.

Web.Config

<add key="ENABLE_PAGE_CACHE" value="true"/>
<add key="CACHE_DURATION_UNIT" value="SECONDS"/><!--SECONDS,MINUTES,DAYS,HOURS-->
<add key="CACHE_DURATION_VALUE" value="10"/>
 <add key="CACHE_CLEAR_PARAMS" value="param1;param2"/><!--query string parameters separated by ; -->

ASPX Page

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace CachingExample
{
    public partial class _Default : Page
    {
        protected void Page_Load(object sender, EventArgs e)
       {
           if(!IsPostback)
          {
               //GetPageContentFromDB
               if(Convert.ToBoolean(ConfigurationManager.AppSettings["ENABLE_PAGE_CACHE"]) 
               CachePage();
            }
            
        }
    }
}

CachePage() Method

protected void CachePage()
        {
            try
            {
                string sCacheDurationUnit = ConfigurationManager.AppSettings["CACHE_DURATION_UNIT"];
                int iCacheDurationValue = Convert.ToInt32(ConfigurationManager.AppSettings["CACHE_DURATION_VALUE"]);
                string [] saCacheVaryParam = ConfigurationManager.AppSettings["CACHE_CLEAR_PARAMS"].Split(';');

                switch (sCacheDurationUnit)
                {
                    case "SECONDS":
                        Response.Cache.SetExpires(DateTime.Now.AddSeconds(iCacheDurationValue));
                        break;
                    case "MINUTES":
                        Response.Cache.SetExpires(DateTime.Now.AddMinutes(iCacheDurationValue));
                        break;
                    case "HOURS":
                        Response.Cache.SetExpires(DateTime.Now.AddHours(iCacheDurationValue));
                        break;
                    case "DAYS":
                        Response.Cache.SetExpires(DateTime.Now.AddDays(iCacheDurationValue));
                        break;
                    default:
                        Response.Cache.SetExpires(DateTime.Now.AddSeconds(iCacheDurationValue));
                        break;
                }
                
                Response.Cache.SetCacheability(HttpCacheability.Public);
                Response.Cache.SetValidUntilExpires(true);

                foreach(string sCacheVaryParam in saCacheVaryParam)
                    Response.Cache.VaryByParams[sCacheVaryParam] = true;

            }
            catch (Exception ex)
            {
                LogError("Caching error " + _oSessionInfo.sMachineId + ".", _oSessionInfo, null, ex);
            }
        }

c# - StreamWriter Performance

I have written several programs that read data from raw input text files,extract required fields and write to tab delimited output text files.The files are usually few GB in size.I wanted to test the performance of the StreamWriter class and below are the results.

StreamWriter when used with a buffer size greater than the default buffer size of 1024 KB performed better.

Run 1: 350 MB Input file with default buffer


using System;
using System.Diagnostics;
using System.IO;
using System.Text;

namespace FileWriterPerf
{
    class Program
    {
        static void Main(string[] args)
        {
            Stopwatch stopWatch = new Stopwatch();
            stopWatch.Start();
            try
            {
                using (StreamWriter oWriter = new StreamWriter(@"c:\File1.txt"))
                {
                    foreach (string sLine in File.ReadLines(@"c:\File.txt"))
                        oWriter.WriteLine(sLine);

                    oWriter.Flush();
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            stopWatch.Stop();
            TimeSpan ts = stopWatch.Elapsed;

            string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",
                ts.Hours, ts.Minutes, ts.Seconds,
                ts.Milliseconds);
            Console.WriteLine("RunTime " + elapsedTime);
            Console.Read();
        }
    }
}

Run 2: 350 MB Input file with 64MB buffer size

using (StreamWriter oWriter = new StreamWriter(@"c:\File1.txt",true,Encoding,ASCII,65536))

Run 3: 2 GB Input file with default buffer size

using (StreamWriter oWriter = new StreamWriter(@"c:\RawFile1.txt"))

Run 4: 2 GB Input file with 64MB buffer size

using (StreamWriter oWriter = new StreamWriter(@"c:\RawFile1.txt",true,Encoding,ASCII,65536))

c# - StreamReader vs File.ReadLines

Performance testing
Machine Configuration: Dell E6420 4 GB Ram 32- Bit i-7 Core (cores dont matter in this case.Parallel test for later)
Input File: 350+ MB tab delimited txt file

StreamReader


using System;
using System.Diagnostics;
using System.IO;

namespace FileReaderPerf
{
    class Program
    {
        static void Main(string[] args)
        {
            Stopwatch stopWatch = new Stopwatch();
            stopWatch.Start();
            try
            {
                  using (StreamReader oReader = new StreamReader(@"c:\File.txt"))
                  {
                      string sLine = oReader.ReadLine();
                      while (sLine != null)
                      {
                          Console.WriteLine(sLine);
                          sLine = oReader.ReadLine();
                      }
                  }                
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            stopWatch.Stop();
            TimeSpan ts = stopWatch.Elapsed;

            string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",
                ts.Hours, ts.Minutes, ts.Seconds,
                ts.Milliseconds);
            Console.WriteLine("RunTime " + elapsedTime);
            Console.Read();
        }
    }
}

StreamReader using a larger buffer size

using (StreamReader oReader = new StreamReader(@"c:\File.txt",Encoding.ASCII,false,8092))

File.ReadLines

using System;

using System.Diagnostics;

using System.IO;

namespace FileReaderPerf

{

    class Program

    {

        static void Main(string[] args)

        {

            Stopwatch stopWatch = new Stopwatch();

            stopWatch.Start();

            try

            {

                 foreach(string sLine in File.ReadLines(@"c:\File.txt"))

                            Console.WriteLine(sLine);

            }

            catch (Exception ex)

            {

                Console.WriteLine(ex.Message);

            }

            stopWatch.Stop();

            TimeSpan ts = stopWatch.Elapsed;

            string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",

                ts.Hours, ts.Minutes, ts.Seconds,

                ts.Milliseconds);

            Console.WriteLine("RunTime " + elapsedTime);

            Console.Read();

        }

    }

}

c# - Managed Parallelism,Threading using Task Parallel Library

One of my recent task was to migrate the .Net 2.0 code for processing a few thousand files.The original code used Managed Threading using ThreadPool. I wanted to update this code using .Net4.0 Task Parallel Library's Parallel.Foreach for this task.(Source: http://msdn.microsoft.com/en-us/library/ff477033.aspx)

Below is a very very trivial example.

In the code below I am getting all the folders in a given directory and processing them in parallel using Parallel.Foreach. I am using Environment.ProcessorCount(Source: http://msdn.microsoft.com/en-us/library/system.environment.processorcount.aspx ) to get the total number of core processors on my server to control the total number of cores being used for processing.In the first example I am using all the 8 cores on my server.

using System;

using System.Threading.Tasks;

using System.IO;

namespace ManagedParallelism

{

    class Program

    {

        static void Main(string[] args)

        {

            try

            {

                DirectoryInfo oDirectoryInfo = new DirectoryInfo(@"C:\MyFolder");

                Parallel.ForEach(oDirectoryInfo.GetDirectories(), new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount }, (oDirectory) =>

                {

                        Console.WriteLine("TIMESTAMP: {0} INFO: PROCESSING DIRECTORY:{1}", DateTime.Now, oDirectory.Name);

                        ProcessDirectory(oDirectory);

                        Console.WriteLine("TIMESTAMP: {0} INFO: COMPLETED DIRECTORY:{1}", DateTime.Now, oDirectory.Name);

                        

                });

            }

            catch (Exception ex)

            {

                Console.WriteLine(ex.StackTrace);

            }

            Console.Read();

        }

        /// <summary>

        /// Function to process each of the sub directories

        /// </summary>

        /// <param name="oDirectory"></param>

        private static void ProcessDirectory(DirectoryInfo oDirectory)

        {

            //ToDo: Add code to process each sub directory in the Raw Files Folder

            //throw new NotImplementedException();

        }

    }

}

By changing the above code to 

Parallel.ForEach(oDirectoryInfo.GetDirectories(), new ParallelOptions { MaxDegreeOfParallelism = (Environment.ProcessorCount - 4)}

parallelism can be limited to 4 cores.This value would ideally come from a configuration file.

Task Parallel Library does make threading easy !